Arteries can be blocked gradually by deposition of fatty material or suddenly by a blood clot. Clots in blocked arteries can either be mechanically removed by devices or dissolved by medicines. Clot dissolving medicines are known as thrombolytic agents (e.g. streptokinase, urokinase, tissue type plasminogen activator, tenecteplase etc) can open blocked arteries in heart attack. Other important medications to given are antiplatelet agents, which inhibit the action of blood cells known as platelets which help in clot formation (e.g. aspirin, clopidogrel, cilostazol). Cilostazol is given mostly in those with disease of peripheral arteries rather than coronary arteries (blood vessel supplying oxygenated blood to the heart). Medicines lowering blood cholesterol levels known as statins (e.g. atorvastatin, simvastatin, rosuvastatin, lovastatin) are also given to prevent the deposition of fatty material within the arteries.